1. Field of the Invention
The present invention relates to a lateral pipe lining material for lining a lateral pipe that branches off from a main pipe, and a lateral pipe lining method using the lateral pipe lining material.
2. Description of the Prior Art
A pipe lining method is known wherein an inner peripheral surface of an aged sewer pipes or other underground pipe is lined and repaired without the pipe being removed from the ground (for example, see U.S. Pat. No. 5,225,121).
In the pipe lining method, a pipe lining material is used which is comprised of a flexible tubular resin absorbing material impregnated with a setting resin with its outer peripheral surface being covered with a highly airtight film. The pipe lining material is everted and inserted into the pipeline under fluid pressure, and pressed against an inner peripheral surface of the pipeline. Heat is then applied to the pipe lining material to cure the setting resin contained therein, thereby lining the inner peripheral surface of the pipeline.
A method that can be applied to a lateral pipe branching out from a main pipe is disclosed in, e.g., U.S. Pat. No. 5,329,063. In this method, a flange formed on one end of a lateral pipe lining material is disposed inside a pressure bag and placed on a setting nozzle of a work robot guided into the main pipe, and the work robot is driven so that the flange will be attached tightly to a peripheral edge of an opening of a lateral pipe of the main pipe. Feeding compressed air into the pressure bag will cause the lateral pipe lining material to be subjected to the pressure of the compressed air and to be everted and inserted from the main pipe into the lateral pipe toward the ground level side. When the lining material has been everted and inserted over the entire length of the lateral pipe, the lateral pipe lining material is heated while being pressed against the inner peripheral surface of the lateral pipe and the thermosetting resin contained therein is cured. This causes the inner peripheral surface of the lateral pipe to be lined and repaired. Once the curing of the lateral pipe lining material is complete, the everted end portion of the lateral pipe lining material that protrudes toward a collector that opens to the ground level is cut off, and the work robot is removed from the pressure bag and main pipe to complete the lateral pipe lining process sequence.
However, the operation for removing the everted end portion of the lateral pipe lining material that protrudes toward the collector may not necessarily be possible due to local conditions at the ground level. In addition, a problem may arise in that the operation for removing the ground level-side terminal part of the lateral pipe lining material will be difficult when the lining of the lateral pipe extends part-way along the lateral pipe rather than over the entire length.
It is therefore an object of the present invention to provide a lateral pipe lining material and lateral pipe lining method whereby all operations can be performed from the main pipe side, and the lateral pipe can always be reliably lined regardless of the conditions at the ground level.